Arrived to do a multi system performance maintenance. Set up for combustion analysis temperature split and static pressure tests. Verified operation of all mechanical and electronic components of the furnace. Checked blower for cleanliness and to see if there is any play in the bearings. Checked systems heat exchanger to ensure proper venting of flue gas. Went to the attic and verified operation of the air handler system. System did not operate at a heat pump due to the temperature but switched over to electric heat seamlessly. Verified operation and cleanliness of each mini split unit. Found that the head in the office is coated in bacterial growth. Replaced filters in the furnace and air handler. Furnace, air handler, and mini split systems are all operational at this time.